d) use host part from rpm-config, and rest from package metadata.
and then one would be able to change report database
by modifying only one package.
Something like:
rpm-config %{bugreporthost} = http://bugzilla.redhat.com/
package %{name} = bacula
--> %{bugreporthost}/%{name}
--> http://bugzilla.redhat.com/bacula